Method and article for producing shaded designs



April 16, 1940. w SWAYSLAND 2,197,015

METHO AND ARTICLE FOB PRCDUCING SHADED DESIGNS Filed June 4, 1956 LEAD OTHER BLACK .l/LPll/DE MERWROUS JULPHIDE INVENT OR WILLIAM 'swAYsLAND Patented Apr. 16, 1940 PATENT ormai;

METHOD AND ARTICLE Foa PnoDUciNG -snADED DESIGNS Willia'inrSwaysland, Cleveland, Ohio l Application June 4, 193s, serial No. 83,553

This invention relates to a method and article for producing shaded designs.

In preparing material for photographic reproduction -it is often desirable to shade certain selected.portions of. an image so that the eect produced by photographing the prepared subject matter is similar to a Ben Day print. The present invention relates to an arrangement of the desired shading design photographically invisible on a prepared board adapted to receive an artists line drawing or on' a separate sheet of lighttransmitting or transparent material adapted to be superimposed uponI a simple/ line drawing of any sort and to a development of the design thereafter in a manner to provide a photographically visible design over certain selected portions of the line drawing.

One of the objectsof the present invention is to provide a new and improved sheet with pre- 0 pared discontinuous areas thereof forming stipplir'tg;y shading, lines, cross-hatching or any desired species of design, together with a suitable developer for changing the photographic visibility of. the shading design. e

Another object of ,the present 'invention is to provide a sheet with a suitable design arranged in discontinuous areas thereon adapted for development in selected areas of a line drawing,` together with a developer for-changing the photographic visibility of the design and in which all v ,oi-the materials involvedl'are free from obnoxious odors or deleterious effect upon hair brushes and the like, all of which form objectionable features in products heretofore used in this art. Another feature of the present invention is the provision upon `my improved sheet of -a suitable design in disconnected areas, said-design being of such a nature that it does not deteriorate upon long exposure to atmosphere or to bright sun- 40 light, together with a developer. for changing the photographic visibility of said design, leaving said design in such a stable condition thatoit will remain indeilnitely in its developed state.

Another object of thevv present invention is to provide new materials for printing white or light colored dots or other designs upon sheet material and new developers for changing the photographic visibility of said dots or designs. Y

Another object of my invention is tolprovide '50 a prepared sheet with discontinuous areas of a photographically invisible shading design, these l areas being o1 two dierent substances adapted;

to be separately developed. Such areas may be of different size and shape, it desired, and they 5s may be developed'selectively to provide two different designs or, if beth are developed together, they will provide a.third design. My invention covers the method of forming a design by such selective development of areas of different chemical composition. 5

Another object of the present'invention is t'o provide a new method of forming a shaded design over desired portions of an image comprising printing designs upon sheet material with a photographically invisible sulphide and thereafter converting certain of the printed design areas to a photographically visible sulphide over desired portions of the image.

Another objectof the present invention is to provide a novel method for afllxing a translucent 15 or transparent design-bearing sheet to an imagej bearing surface.

The invention consists in the various forms of structure. chemical compositions and steps in method or process'hereinafter described and illustrated in the drawing, and the essential features thereof will be 'set forth inthe claims.

In'the drawing. Fig. l represents a portion of a sheet with one form of my improved shading design in undeveloped condition thereon; Figs. 2, 3 and 4 are views of portions of sheets having the shading design partially developed; while Figs. 5 and 6 show portions of a sheet of drawing 'board illustrating a method of forming a shading design thereon. All of the views are greatly enlarged for the purpose of illustration.

In all sheets bearing a suitable invisible shading design which is later treated to produce the l desired shadel effects over ycertain portions of a `line drawing heretofore used, so far as Ik know, wherever the variation in the shaded design has depended upon chemical developments of such design, other than by the use of silver salts and photographic processes, the materials used have h ad an obnoxious odor or a deleterious effect upon the brushes used in applying the chemicals y or some other defect which has prevented their general adoption in the art. I have provided such a 'sheet having a design produced therein which is stable, and without obnoxious odor, together with a developer for changing the photographic visibility of selected lportions of the design which produces a design of different color which is also stable, and both the developed design and developer used are without obnoxious odor and without other objectionable commercial defects.

My invention comprises novel .substances and methods for the formation of white or lightcolored dots or other shading design either upon 55 shading effect in such portions of the line drawing'or other image.

In one manner of forming disconnected areas of a shading design such as dots, cross-hatching and the like, I use an insoluble salt of mercury such as mercurous chloride or mercurous sulphate orany other suitable salt of mercury whicli is insoluble and of a color to produce the desired visibility. For instance, in Fig. 1 I have illus-- trated a portion of aprepared sheet in which the shading design takes 'the form of dots which are -greatly enlarged for the purpose of illustration. The dots shown in the various gures are of different sizes for a purpose later described and, while all of the dots may be formed in the same manner, I shall describe a specialized form in which certain of the dots indicated at I inFig. 1 are printed from a salt of mercury such as I have just described.l In preparing this sheet of Fig. l,

the dots are printed' either by mixing the mercury salt with a suitable printing varnish or the dots may be printed with a plain varnish and themercury salt dusted on before the varnish 'dries. Mercurous chloride will form a white dot and the showing of Fig. 1 reproduces these dots with a dotted effect, whereas in actual practice they would be substantially invisible. If the mercurous chloride dots of Fig. 1 are produced on aV white drawing board or paper surface the artist may produce a line image on this surface and thereafter develop the dots lying within certain selected portions of the area of the image so as to give a shaded effect thereto.

A suitable developer for the salts of mercury above described is one containing a reducing sulphur content so that the dots or shading designs arev changed to a dark compound which I presume to be a combination of mercury and mercurous sulphide. Such a suitable developer is found in metallic sulphites, hyposulphites and thiosulphates. For' instance, sodium thiosulphate provides a suitable reducing sulphur compound and the addition of a certain amount of sodium sulphite thereto makes the compound more stable. The reducing action of ythe sulphur compound is accomplished more rapidly in an alkaline solution and therefore I prefer to add an alkaline salt, such as sodium carbonate. I avoid suchcompounds as sodium hydroxide because they eat the brushes which are usually used for applying the developer.

The white or light colored dots of mercury salts when developed and darkened by the use of the foregoing described developer are unstable unless I add a substance to prevent oxidation. Such a substance is found in sodium hypophosphites, aldehydes, stannous compounds or antimonious compounds. I prefer, however, a sugar, such as dextrose or corn sugar, because it has no obnoxious odor and no other bad effects.

Where the .dots are originally printed by mixing of the lmercury salt with a suitable printing varnish, I find it advisable to add to the developer a small amount of a solvent'for the printing varnish so that the developer may more easily attack the printed dots. I find that alcohol isgenerally a suitable solvent for this purpose.

. ine. \with this material will be impregnated with a Atypical developer solutionl 'for dots"4 printed from a mixture of the insoluble mercury salts and printing varnish is the following composiv When the lsheet of Fig. l has been treated,-

with a developer containing a reducing sulphur compoundv as described, the small dots will develop black in the treated area as illustrated in Fig. 3. f

y,Another manner of forming the disconnected areas of a suitable shading design is to print the design on the desired surface using a' white sulphide which may be later developed with a soluble metallic salt of a sort 'which forms a black ,sulphide so as to` change the -visibility of the shading design areas. A suitable white sulphide is zinc sulphide and I have illustrated hcertain dots Il of Fig. 1 as formed uponfa suitable surface by printing. Here again 'the printing may be done with a plain varnish and the zinc sulphide in powder form dusted on before the varnish dries. Any soluble metallic salt carrying a metal which forms a vblack sulphide may then be passed by a brush over the dots of zinc sulphide whereupon a chemical lreaction occurs,

changing'the zinc sulphide or at least a portion thereof to another metallic sulphide of blackor dark gray color. Such a. result is shown in the developed area. of Fig. 2. A suitable vdeveloperis an acidiiied solution of lead acetate which will form av lead' sulphide on the prepared spots. However I donot desire to limit myself to lead because there are other well known soluble metallic salts which provide suitable metals to produce black sulphides, such as salts'of copper, cobalt, nickel or others.

Where it is desired izo/,prepare a white drawing j board or other surface for later use by an artist vin preparing a line image thereon,l I nd a suitable method of forming the` zinc sulphide dots in the paper is as follows:

A white soluble zinc salt such as zinc chloride or zinc acetate may be printed in suitable design upon` the surface of the paper or other fibrous material using a suitable vehicle such as glycer- Obviously the surface of the areas coated certain amount of the soluble zinc salt. Fig. 5 is an illustration greatly exaggerated showing a paper or other brous surface printed withI such a white soluble zinc salt. Thereafter I wash the printed surface with ammonium sulphide, sodium sulphide or other-suitable compound of sulphur to convert the soluble zinc salt which has impregnated the surface of the paper intov insoluble zinc sulphide. This being white is substantially invisible on the white drawing surface -and, being embedded in the surface,l does not interfere y,with the later production of the line image on the paper surface by the artist. The

prepared sheet is represented in Fig. 6. A selected area of such a prepared surface may be developed by the use of a water soluble 'metallic salt solution such as I have described above, for instance, lead acetate, which will change the zinc sulphide areas to a lead sulphide or other black sulphide area. This result is the same as shown in Fig. 2, except that a sheet prepared as in yessary but any line drawing of an image may be shaded in'desired areasr by superimposing the light-transmitting sheet bearing the shading design over the underlying image and thereafter producing the desired shading effect in selected areas of the image by development of the shading design. To this end the shading design is producedupon the overlay sheet in a color phoois sulphide shading areas has no visible effect upon tographically invisible against the back ground of the underlying sheet. Thereafter by the application of a suitable developer, generally brushed on, selected portions ofthe shading design are chemically developed to render them photographically visible in selected portions of the area of the underlying image and thereafter the composite sheet is photographed forfurther reproduction.

In such a process using anoverlay sheet the shading design is applied to a sheet of translucent or vtransparent material having suitable characteristics such as thinness, flexibility, non-stretchable and strong, such-as a specially prepared paper cellophane, or cellulose acetate product.

My preferred method for producing the shading design upon such an overlay sheet is to first print the design which may comprise dots, stippling, lines, cross-hatching orany desired design using a plain printing varnish. The chemical substance forming the dots or design is then dusted on the varnish in powder form before the varnish dries. These shading areas may biel covered with a white insoluble salt of mercury, such as the mercurous chloride or mercurous sulphate mentioned above, in which case they will be developed by the use of the above described developer containing a reducing sulphur compound which will provide darkened shading areas containing mercurous sulphide. -Alternatively, the `shading areas may be printed and prepared using a white sulphide which may be later developed with a soluble metallic salt which forms a black sulphide, for instance, a salt of lead, copper, cobalt, nickel, etc.

A suitable method for securingthe overlay sheet to the underlying surface, particularly when the overlay sheet is of cellophane, is to soften without dissolving the waterproof coating of the cellophane sheet as by the application of a suitable solvent, such as methyl cellosolve to the under surface thereof. vThe cellophane sheet when thus treated may be laid upon-the base surface and pressed lightly with the fingers at various points, whereupon it will permanently adhere vto the underlying surface.'

Either of the above described combinations of a preparedl shading design and, its developer may be used separately either on the same surface Iused by the artist for producing a line drawing or upon an overlay sheet as described, or I may produce upon one surface shading designs produced partly by means of a white sulphide and partlgvv by means of a white insoluble salt of mercury. In the latter case I provide a new process for producing a number of4 shading efthe insoluble mercury salts and the developer for the shading areas of insoluble mercury salts has no visible effect upon the white sulphidev areas. ff

Referring now to Figs. 1 to 4, a sheet prepared as in Fig. 1 having dots I0 of mercurous chloride or its equivalent and dots II of zinc sulphide or other equivalent substance may be developed in selected areas in one of several ways. The line I2 may represent a line of an image produced either upon thefsame surface as the dots IIl and I I in one manner suggested above, or an image on an underlying surface with the dots I0 and II produced upon an overlay sheet as suggested in a second manner of using my invention. In either case a selected areaof the sheet delineated by .the line I2 may have a suitable developer applied thereto, as by means of a brush, to change the photographic visibility of the dots I0 or of the dots II, or of both dots. For instance, in Fig. 2 the dots II have been developed as shown at I3 using a water soluble metallic salt such as lead acetate or the like to render them black and photographically visible. However, as shown in Fig. 3 the dots I0 may be developed to a black or dark color by the use of a reducing sulphur compound as shown at I4 to produce a different shading effect, while in Fig. 4 by using two developers both series of dots have been developed to a dark color to produce still a third shading effect. It will be understood of course that one effect may be produced over one portion of the image, a secondy effect over another` portion of Ithe image and a third effect over still another portion of the image, if desired. a

, In the process described in the foregoing paragraph, I am` able to develop one design in one portion of the sh'eet and another design in another portion ofthe sheet, each quite definitely and independently of any effect on the design which is to be left undeveloped in the area treated. This is obviously true where one portion of the sheet contains zinc sulphide adapted to be blackened by treatment with the water solution of lead acetate which will not attack the varnish vehicle used in printing, say mercurous chloride dots. On the other hand, a developer for the mercurous chloride design containing a reducing sulphur compound will not change the portion of the sheet treated with zinc sulphide.

I do not limit myself to shading designs of any particular shape or size, nor wherel use dots do I limitmyself to round dots or to dots of different sizes. two separate sets of dots identical except for the substance with which they are printed or.

For instance there might be the surface thereof impregnated with zinc sulphide. f f

4. In a composite sheet for photographic reproduction comprising a surface containing an image and a shading sheet of substantially transparent material superimposed on said surface, said sheet having discontinuous areas covered with a composition of matter including mer- `curous sulphide and a substance adapted to prevent oxidation thereof upon exposure to atmosphere.

5. In a. composite sheet for photographic reproduction comprising a surface containing an image and a shading sheet of substantially transparent material superimposed on said surface, said sheet having discontinuous areas covered with a composition of matter including mercurou's vsulphide and a sugar.

6. The method of forming Ia shaded design in selected areas of a sheet having a liquidpermeable surface comprising'forming said design on said sheet using a soluble surface-permeating zinc compound, and thereafter treating said compound to change the sheet-impregnating portion thereof to insoluble zinc sulphide whereby to form a design substantially wholly embedded within the normal surface of the s heet.-

WILLIAM SWAYSLAND. 

